Research underway at the University of Saskatchewan will help policymakers develop strategies for reducing the carbon footprint of agriculture.
This research examines the implications of adding high fibre alternative feed ingredients into swine rations, also exploring greenhouse gas generation through the pork production cycle using a model developed by Agriculture and Agri-Food Canada.
The study focuses on field peas, which benefit the soil, and wheat middlings, a co-product of flour production.
Dr. Denise Beaulieu, Assistant Professor Monogastric Nutrition with the university’s College of Agriculture and Bioresources, said researchers find they can include these high fibre ingredients in rations at high levels with no adverse effects on productivity.
“We’re using a model developed by Agriculture Canada, so I would like to acknowledge their contribution to this project,” said Dr. Beaulieu. “They are adapting the model primarily used before for beef cattle. The model will take everything into account from growing the crops, taking the by-products off the crop, producing feeds from those crops, feeding it to the pigs, greenhouse gas production within the barn, manure production in the barn and then the animals going to market.”
We are then combining this data in one model to look at the effect of different diets and by-product inclusions on the overall carbon footprint.
“One of the reasons we’re looking from growing the crop to sending the pigs to market is because one of the major sources of greenhouse gas output from pork production comes from producing the feed,” she said. “So anything we can do to reduce that impact will be significant.”
“I worked for several years looking at feeding by-products to pigs and looking at their production. We know that these are a more economical way of producing pork. A lot of these by-products are high in fibre,” said Dr. Beaulieu. “My first question because these fibres ferment in the large intestine, is whether this would increase or have some small effect on the actual greenhouse gas output from the pig itself. Then secondly, reading a report of a large study by the Food and Agriculture Organization from the UN published a few years ago on an extensive examination of all the literature related to carbon footprint pork production. I noticed no Canadian studies included in this fairly comprehensive report.”

The main objectives of her study are the overall carbon footprint and provide some data for use in models for pork produced here in Canada or especially in western Canada, and how by-products or alternative feedstuffs affect that carbon footprint.
“We’re using two different feed ingredients, one including high levels of peas in the diet of finishing pigs, up to 40 per cent peas. We know that including peas in a crop rotation can decrease the overall carbon footprint and it’s good for the soil to produce further crops,” she said. “Secondly, we include a by-product of flour production, wheat middlings in our diet, a high of wheat middlings up to about 30 per cent a by-product of wheat production and flour production, relatively high in fibre.”
Beaulieu said they’re running several experiments looking at the inclusion of these in the diet of pigs and do the pigs’ grow if not included in their diet. What happens in the production of manure when stored and the gas production of this manure. What is the nitrogen retention in these pigs looking at protein retained in the pigs, and finally putting pigs in specialized chambers at the Prairie Swine Center to measure gas production from the pigs?
“Specifically from greenhouse gas emissions, we are looking at the effects on the manure, and we’re looking at different ways. For example, does the greenhouse gas emissions change depend upon how long they store the manure,” she said. “We had the pigs in chambers, measured the greenhouse gas with and without the pigs in those chambers so we can separate the gas produced by the pig and from the manure, and the greenhouse gas produced from the pig. We’re looking at the typical greenhouse gases produced, specifically CO2 and nitrous oxide.”
Beaulieu said while learning nothing new but showed it wasn’t anything new.
“We can formulate diets with up to 40 per cent peas in the diets, and the pigs grow just fine and large amounts of wheat mids too, and the pigs grow just fine,” she said. “We will incorporate data into models to look at the overall carbon footprint, but we can certainly include these in the diets, even in terms of economics.” •
— By Harry Siemens